Suzuki XL7 2007 Service Manual page 215

Conditions for Setting the DTC
The ECM determines that the efficiency of the catalyst
has degraded below a calibrated threshold for more than
4 seconds.
Action Taken When the DTC Sets
DTCs P0420 and P0430 are Type A DTCs.
Conditions for Clearing the DTC
DTCs P0420 and P0430 are Type A DTCs.
Diagnostic Aids
Inspect for the following conditions, which may cause a
catalytic converter to degrade:
• An engine misfire
• High engine oil or high coolant consumption
• Retarded spark timing
• A weak or poor spark
• A lean fuel mixture
• A rich fuel mixture
• A damaged oxygen sensor or wiring harness
Reference Information
Schematic Reference
"Engine Controls Schematics"
Connector End View Reference
• "Engine Control Module Connector End Views"
• "Engine Controls Connector End Views"
Electrical Information Reference
• "Circuit Testing: "
• "Connector Repairs: "
• "Testing for Intermittent Conditions and Poor
Connections: "
• "Wiring Repairs: "
DTC Type Reference
"Powertrain Diagnostic Trouble Code (DTC) Type
Definitions"
Scan Tool Reference
• "Scan Tool Data List - Engine Controls - 3.6L (LY7)"
• "Scan Tool Data Definitions - Engine Controls - 3.6L
(LY7)"
• "Scan Tool Output Controls - Engine Controls - 3.6L
(LY7)"
Engine General Information and Diagnosis:
Circuit/System Testing
1. Verify there are no HO2S or misfire DTCs set.
➢ If there is an HO2S or misfire DTC set, refer to
"Diagnostic Trouble Code (DTC) List - Vehicle
Diagnostic Information: " to diagnosis the
applicable DTC, before proceeding with this
diagnostic procedure.
2. Verify the following conditions do not exist with the
appropriate catalytic converter:
– Dents
– A severe discoloration caused by excessive
temperatures
– Road damage
– An internal rattle caused by damaged catalyst
substrate
– Restrictions
➢ If a condition is found, replace the appropriate
catalytic converter.
3. Verify the following conditions do not exist with the
exhaust system:
– Leaks
– Physical damage
– Loose or missing hardware
– Properly torqued HO2S
➢ If a condition is found, repair the exhaust system.
4. Verify the following conditions do not exist with the
appropriate HO2S 2:
– A grounded wiring harness
– Damage
➢ If a condition is found, replace the appropriate
HO2S 2.
5. If no physical condition is detected and the HO2S 2
is as active as the HO2S 1 after operating the engine
at 1,500 RPM for 1 minute and then returning to a
stabilized idle, then replace the catalytic converter.
Repair Instructions
Perform the "Diagnostic Repair Verification - Vehicle
Diagnostic Information: " after completing the diagnostic
procedure.
• "Catalytic Converter Replacement - Left Side: "
• "Catalytic Converter Replacement - Right Side: "
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